Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/03—Powdery paints
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/78—Preparation processes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D167/00—Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain; Coating compositions based on derivatives of such polymers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31786—Of polyester [e.g., alkyd, etc.]
  • Y10T428/31794—Of cross-linked polyester

Definitions

• the invention relates to the production of colored powder coatings, in particular for use in powder coating compositions.
• the invention also relates to the use of the powder coating materials obtained for coating substrates, and to the coated substrates obtained in this way.
• Powder coatings are generally produced using conventional extruder technology.
• the components of the powder coating i.e. Binder, hardener and optionally pigments and other additives, as solids in the required proportions, dry premixed and then melted and mixed thoroughly in an extruder at the lowest possible temperature.
• the resulting, optionally colored, extrudate is then rolled out into a thin layer, cooled and broken into coarse granules, which are ground in a mill to produce the finished powder coating.
• binders in a specific viscosity range can be anchored with the extruder.
• the broad particle size range that forms during milling in a range of, for example, 0.1 to 500 micrometers requires additional sieving and milling processes for specific applications. Beyond that it is Accruing fine grain disadvantageous for health and processing reasons.
• Nonaqueous dispersion A polymer or a polymer precursor, for example a polyester, is introduced into a dispersion medium at a temperature of, for example, below 200 ° C.
• pigments are added to the dispersion, preferably after the dispersion has cooled.
• the corresponding powder particles are obtained by further cooling, separating and drying the resulting particles.
• the object is achieved by a process forming the subject of the invention for producing a powder coating composition based on polyester
• the homogeneous mixing of the components using shear forces can take place, for example, in a time of 10 to 100 minutes, depending on the type of starting components, in particular depending on the type and amount of the pigments used.
• the temperature in the dispersion medium can be increased
• the reaction can be stopped by lowering the temperature.
• the reaction can be stopped at any time by appropriate cooling.
• the process can be continued continuously until the desired final molecular weight has been added before the crosslinker (s) are added.
• the process is preferably continued continuously until a polyester having the desired final molecular weight is obtained. This is achieved by maintaining the temperature in a range, for example between 120 and 280 ° C., in the dispersion medium and distilling off the condensation products, such as water, methanol. This is followed by the production of Powder coating compositions, the dispersion with the composition to be used according to the invention is cooled to temperatures between 60 and 140 ° C. and the crosslinking agent (s) and, if appropriate, further additives are added to the dispersion bath under these conditions. After the dispersion has been cooled, separated and dried by customary processes, the finished colored powder coating results.
• the possibly interposed colored polyester precondensate it can be dispersed after heating to a temperature of 120 to 200 ° C in a dispersion medium, optionally with dispersion stabilizers until the final molecular weight is reached, at a temperature equal to or above the melting temperature of the starting components, for example at 180 up to 280 ° C.
• the crosslinking agent and, if appropriate, the additives can be added to the dispersion medium, and the finished colored powder coating can result after cooling, separation and drying.
• a colored powder coating results after the process according to the invention, the particle structure of which has a homogeneous structure and the particle size distribution is in a narrow range from 10 to 50 millimeters.
• aliphatic oils with a boiling point of 150 to 300 ° C can serve as the dispersion base.
• the oils are usually free of aromatics.
• aromatics can also be present, preferably below 2% by weight.
• the dispersion bath can optionally contain one or more dispersion stabilizers, for example up to 5% by weight, based on the polyester component. These can be customary wetting additives which are introduced into the bath by stirring.
• the polyester precondensate of component A) to be used according to the invention can be prepared in a conventional manner by reaction of polycarboxylic acids, their anhydrides and / or Esters can be made with polyalcohols.
• the esterification can take place in a customary manner, for example in a nitrogen atmosphere at elevated temperature, for example between 120 and 200 ° C., to the desired viscosity, for example less than 1000 mPa.s, in particular less than 500 mPa.s.
• Dicarboxylic acid components are preferably used as the polycarboxylic acid component.
• the dicarboxylic acid components can be aliphatic, cycloaliphatic and / or aromatic dicarboxylic acids and / or their anhydrides. These are, for example, adipic acid, sebacic acid, dodecanoic acid, 1,4-cyclohexanedicarboxylic acid, dimer fatty acid, phthalic acid, isophthalic acid, terephthalic acid.
• the acids can be used individually or as a mixture.
• the carboxylic acids can also contain other functional groups, e.g. Sufonic acid groups.
• Preferred polyol components are diols or diols in a mixture with polyols.
• diols are aliphatic and / or cycloaliphatic diols, e.g. Ethylene glycol, diethylene glycol, propanediol, hexanediol, propylene glycol, cycolhexanedimethanol, neopentyl glycol, hydroxipivalic acid, neopentyl glycol ester.
• triols for example trimethylolpropane, can be used as polyols in a mixture with diols.
• Higher polycarboxylic acids and / or polyols can also be used to increase the functionality of the polyester, for example by introducing carbonyl and / or hydroxyl groups.
• the polyester precondensate can be hydoxy functional and / or carboxy functional.
• the hydroxyl and / or carboxy functions can be introduced by suitable selection of the starting materials and / or their proportions.
• the molar ratio of diol or diol and / or polyol to dicarboxylic acid or dicarboxylic anhydride can be, for example, 1.2: 1 to 0.8: 1.
• Esterification catalysts are, for example, dibutyltin dilaurate, zinc acetate, tin chloride or tetrabutoxytitanate.
• the monomers to be used for its preparation i.e. Polycarboxylic acids or their .Anhydride and polyalcohols, as mentioned above, and in the specified ratio, as component A are used.
• Pigments are used as component B) to be used according to the invention. All organic or inorganic pigments or dyes which are temperature-stable at temperatures of at least 200 ° C. can be used as pigments. Mixtures of different pigments or dyes can also be used. Examples of inorganic pigments are titanium diojcid, iron oxide red, iron oxide brown, iron oxide black, carbon black, chromium titanium yellow, cobalt / aluminum oxide and examples of organic pigments are compounds from the class of the phthalocyanines,
• Chrinacridone azo pigments, vat dyes.
• Effect pigments can also be used, e.g. Pearlescent pigments of the Iriodin type.
• the pigments can also contain fillers familiar to the person skilled in the art, such as, for example, barium sulfate, calcium carbonate, kaolin.
• pigment preparations can also be used in which, for example, the pigments are already predispersed in diols and / or polyols, the diols and / or polyols in turn being components of the polyesters prepared according to the invention.
• Wetting additives or dispersion stabilizers which may be used as component C) can be those which are familiar to the person skilled in the art, for example nonionic and / or ionogenic wetting agents.
• So-called ampholytic copolymers can also be used as wetting additives, for example. They can be monomeric, oligomeric and / or polymeric in nature.
• other conventional paint additives can be added, for example leveling agents, defoamers and catalysts, matting agents (for example coats, textbook on paints and coatings, vol. 3, Colomb Verlag, 1976).
• the resulting polyesters can exhibit thermoplastic behavior and they can contain functional groups via which crosslinking is possible.
• crosslinkers The compounds known to the person skilled in the art can be used as crosslinkers. These are, for example, epojtides, for example based on diglycidyl bisphenol A and
• Triglycidyl isocyanurate Triglycidyl isocyanurate.
• Other crosslinking agents are agents based on aminoplast resins, such as melamine resins, urea resins, dicyandiamide resins.
• Isocyanate crosslinkers can also be used. These are the aliphatic, cycloaliphatic or aromatic di- or polyisocyanates known as lacquer polyisocyanates. The real isocyanate groups can be obtained with beka. could
• Blocking agents such as low molecular weight alcohols, amino alcohols, oximes, lactams or acetoacetic acid derivatives can be blocked in the usual way.
• the amount of crosslinking agent is usually 2 to 50% by weight, for example 2 to 20% by weight, preferably 5 to 10% by weight, based on the polyester component.
• Epoxy / polyester hybrid systems familiar to those skilled in the art can contain up to 50% by weight of crosslinker.
• the binders / hardener systems based on polyesters known in the powder coating sector can be used, for example functional polyester / triglycidyl isocyanurate (TGIC) hardener.
• TGIC triglycidyl isocyanurate
• acidic polyester / epoxy hardener polyester acrylate powder.
• the resulting powder coatings achieve equally good values in comparison to P in terms of their crosslinking temperature and gel time. ulverlacken, the traditional
• the resulting predominantly powdered spherical particles have a homogeneous particle structure with a narrow particle size range, and they are homogeneously pigmented. They can be manufactured, for example, with a number average
• Mn Molecular weight of the binder portion of up to 50,000 g / mol.
• the majority of the particles have a particle size of less than 50 micrometers, preferably less than 40 micrometers and particularly preferably less than 30 micrometers.
• the powders produced according to the invention are used as coating agents for
• Metal or plastic substrates are suitable as substrates.
• the powder coating composition can be applied and baked onto the surfaces to be coated using the methods customary for powder coating, for example electrostatic application via corona discharge or triboelectrics. Layer thicknesses of, for example, 15 to 200 micrometers, preferably 20 to 75 micrometers, can be applied.
• the powder coating systems are stoved under the temperature and time conditions required for complete crosslinking, for example at temperatures of 100 to 250 ° C. and times of 5 to 30 minutes.
• the components are homogeneously mixed for 10 to 60 minutes at 8000 revolutions per minute with the aid of a toothed washer with a diameter of 4 cm.
• FIG. 1 shows particles of a polyester powder coating pigmented with titanium dioxide and produced according to the prior art (NAD process). It can be seen that the titanium dioxide is only located on the periphery of the polyester powder coating particles.
• a large part of the pigments is also agglomerated in the dispersion medium (heat exchanger) and not dispersed in the powder.
• FIG. 2 shows polyester powder coating particles produced according to the invention. It can be seen that the pigments are distributed almost homogeneously in the polyester particles and that there are no additional agglomerates in the dispersion medium.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Medicinal Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Polymers & Plastics (AREA)
• Paints Or Removers (AREA)
• Pigments, Carbon Blacks, Or Wood Stains (AREA)
• Epoxy Resins (AREA)
• Macromonomer-Based Addition Polymer (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Polyesters Or Polycarbonates (AREA)

Priority Applications (13)

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Publications (1)

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Citations (2)

• 1997
  • 1997-12-23 DE DE19757544A patent/DE19757544A1/de not_active Withdrawn
• 1998
  • 1998-12-22 JP JP2000526589A patent/JP2002500238A/ja active Pending
  • 1998-12-22 CA CA002316306A patent/CA2316306A1/en not_active Abandoned
  • 1998-12-22 BR BR9814397-2A patent/BR9814397A/pt not_active IP Right Cessation
  • 1998-12-22 KR KR1020007006932A patent/KR20010033446A/ko active IP Right Grant
  • 1998-12-22 EP EP98965875A patent/EP1042412B1/de not_active Expired - Lifetime
  • 1998-12-22 TR TR2000/01833T patent/TR200001833T2/xx unknown
  • 1998-12-22 PL PL98341371A patent/PL188593B1/pl not_active IP Right Cessation
  • 1998-12-22 AT AT98965875T patent/ATE215591T1/de not_active IP Right Cessation
  • 1998-12-22 DK DK98965875T patent/DK1042412T3/da active
  • 1998-12-22 US US09/582,480 patent/US6368725B1/en not_active Expired - Fee Related
  • 1998-12-22 ES ES98965875T patent/ES2175849T3/es not_active Expired - Lifetime
  • 1998-12-22 AU AU21634/99A patent/AU743577B2/en not_active Ceased
  • 1998-12-22 RU RU2000119799/04A patent/RU2200747C2/ru not_active IP Right Cessation
  • 1998-12-22 CN CN98813776.3A patent/CN1206289C/zh not_active Expired - Fee Related
  • 1998-12-22 PT PT98965875T patent/PT1042412E/pt unknown
  • 1998-12-22 MX MXPA00006253A patent/MXPA00006253A/es not_active Application Discontinuation
  • 1998-12-22 WO PCT/EP1998/008460 patent/WO1999033926A1/de active IP Right Grant
  • 1998-12-22 DE DE59803674T patent/DE59803674D1/de not_active Expired - Fee Related
• 2000
  • 2000-06-15 NO NO20003085A patent/NO20003085L/no not_active Application Discontinuation

Patent Citations (2)

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